In the heat setting of carpet yarns, the yarns are typically laid on a stainless steel conveyor belt and a textile product lays on top of the yarns to hold them in place. This textile product is called a counterband tape. Continuous carpet yarn heat setting machines are commercially available and one supplier is Superba S.A., Mulhouse, France. Some counterband tapes have previously been manufactured from yarns made of the material polymetaphenylene isophthalamide which is commercially available from DuPont under the brand name NOMEX (m-aramid). In the carpet yarn making industry for heat-setting of yarns on SUPERBA brand machines, NOMEX (Meta-aramid fiber available from DuPont) is the raw material of choice for making counterband tapes due to its high temperature resistance. As the working temperature for the tape application increases, the preferred polymer selection is one that can withstand elevated temperatures without heat and hydrolytic degradation due to the combination of heat and moisture. Counterband tapes currently being used in the industry are generally made of polyester and NOMEX yarns. There are a few examples of KEVLAR and TECHNORA (para-Aramid) observed in limited field trials. Due to a wide range of working temperatures applicable in the heat tunnels on Superba machines, the life of the counterband tape is highly dependent on the working temperatures in the application. When the heat tunnel is set at a lower working temperature, the counterband tapes last longer. At the lower end of working temperatures, the end user also has more options in the selection of counterband tapes made with different types of polymers that have lower heat resistance properties than NOMEX. However, as the tunnel working temperature range is increased, the life expectancy of the counterband tape deteriorates rapidly. The heat setting equipment manufacturers typically recommend NOMEX counter band tape at the highest range of tunnel temperatures for heat setting polyester (PET, polyethylene terephthalate) yarns. The NOMEX counterband tape life is extremely limited at the highest end of the tunnel temperature settings as observed in various field runs. Meta-aramid polymer degrades at accelerated rates due to hydrolytic damage at the higher tunnel temperatures. The extent of polymer degradation and weight loss found was significant and rendered the counterband tape ineffective in carrying out the heat and moisture transfer during the normal cycle on the carpet yarn heat setting machines after a few weeks of use.
For nylon carpet yarns which are a lower working temperature material, the NOMEX brand material performed satisfactorily in the counterband tape application. However, the heatsetting temperatures for polyester are higher (i.e., 145° C. in the tunnel section) than for nylon, and as described above the NOMEX material was not as durable under the higher working temperatures. Accordingly, there is a need for a counterband tape for use in the continuous heatsetting of carpet yarns where the yarns are heatset at the higher temperatures suitable for polyester yarns. There is also a need for a tape with a surface texture optimized for use in the heatsetting application.